The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Sotiris E Pratsinis - One of the best experts on this subject based on the ideXlab platform.
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enhanced ag ion release from aqueous Nanosilver suspensions by absorption of ambient co2
Langmuir, 2015Co-Authors: Kakeru Fujiwara, Georgios A Sotiriou, Sotiris E PratsinisAbstract:Nanosilver with closely controlled average particle diameter (7–30 nm) immobilized on nanosilica is prepared and characterized by X-ray diffraction, N2 adsorption, and transmission electron microscopy. The presence of Ag2O on the as-prepared Nanosilver surface is confirmed by UV–vis spectroscopy and quantified by thermogravimetric analysis and mass spectrometry. The release of Ag+ ions in deionized water is monitored electrochemically and traced quantitatively to the dissolution of a preexisting Ag2O monolayer on the Nanosilver surface. During this dissolution, the pH of the host solution rapidly increases, suppressing dissolution of the remaining metallic Ag. When, however, a Nanosilver suspension is exposed to a CO2-containing atmosphere, like ambient air during its storage or usage, then CO2 is absorbed by the host solution decreasing its pH and contributing to metallic Ag dissolution and further leaching of Ag+ ions. So the release of Ag+ ions from the above closely sized Nanosilver solutions in the a...
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toxicity of silver nanoparticles in macrophages
Small, 2013Co-Authors: Anna Pratsinis, Pablo Hervella, Jeanchristophe Leroux, Sotiris E Pratsinis, Georgios A SotiriouAbstract:Silver nanoparticles (Nanosilver) are broadly used today in textiles, food packaging, household devices and bioapplications, prompting a better understanding of their toxicity and biological interactions. In particular, the cytotoxicity of Nanosilver with respect to mammalian cells remains unclear, because such investigations can be biased by the Nanosilver coatings and the lack of particle size control. Here, Nanosilver of well-defined size (5.7 to 20.4 nm) supported on inert nanostructured silica is produced using flame aerosol technology. The cytotoxicity of the prepared Nanosilver with respect to murine macrophages is assessed in vitro because these cells are among the first to confront Nanosilver upon its intake by mammals. The silica support facilitates the dispersion and stabilization of the prepared Nanosilver in biological suspensions, and no other coating or functionalization is applied that could interfere with the biointeractions of Nanosilver. Detailed characterization of the particles by X-ray diffraction and electron microscopy reveals that the size of the Nanosilver is well controlled. Smaller Nanosilver particles release or leach larger fractions of their mass as Ag⁺ ions upon dispersion in water. This strongly influences the cytotoxicity of the Nanosilver when incubated with murine macrophages. The size of the Nanosilver dictates its mode of cytotoxicity (Ag⁺ ion-specific and/or particle-specific). The toxicity of small Nanosilver ( 10 nm). Direct silver nanoparticle-macrophage interactions dominate the Nanosilver toxicity at sizes larger than 10 nm.
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quantifying the origin of released ag ions from Nanosilver
Langmuir, 2012Co-Authors: Georgios A Sotiriou, Andreas Meyer, Sven Panke, Jesper T N Knijnenburg, Sotiris E PratsinisAbstract:Nanosilver is most attractive for its bactericidal properties in modern textiles, food packaging, and biomedical applications. Concerns, however, about released Ag+ ions during dispersion of Nanosilver in liquids have limited its broad use. Here, Nanosilver supported on nanostructured silica is made with closely controlled Ag size both by dry (flame aerosol) and by wet chemistry (impregnation) processes without any surface functionalization that could interfere with its ion release. It is characterized by electron microscopy, atomic absorption spectroscopy, and X-ray diffraction, and its Ag+ ion release in deionized water is monitored electrochemically. The dispersion method of Nanosilver in solutions affects its dissolution rate but not the final Ag+ ion concentration. By systematically comparing Nanosilver size distributions to their equilibrium Ag+ ion concentrations, it is revealed that the latter correspond precisely to dissolution of one to two surface silver oxide monolayers, depending on particle ...
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engineering Nanosilver as an antibacterial biosensor and bioimaging material
Current opinion in chemical engineering, 2011Co-Authors: Georgios A Sotiriou, Sotiris E PratsinisAbstract:The capacity of Nanosilver (Ag nanoparticles) to destroy infectious micro-organisms makes it one of the most powerful antimicrobial agents, an attractive feature against ‘super-bugs’ resistant to antibiotics. Furthermore, its plasmonic properties facilitate its employment as a biosensor or bioimaging agent. Here, the interaction of Nanosilver with biological systems including bacteria and mammalian cells is reviewed. The toxicity of Nanosilver is discussed focusing on Ag+ ion release in liquid solutions. Biomedical applications of Nanosilver are also presented capitalizing on its antimicrobial and plasmonic properties and summarizing its advantages, limitations and challenges. Though a lot needs to be learned about the toxicity of Nanosilver, enough is known to safely use it in a spectrum of applications with minimal impact to the environment and human health.
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Nanosilver on nanostructured silica antibacterial activity and ag surface area
Chemical Engineering Journal, 2011Co-Authors: Georgios A Sotiriou, Alexandra Teleki, Adrian Camenzind, Frank Krumeich, Andreas Meyer, Sven Panke, Sotiris E PratsinisAbstract:Nanosilver is one of the first nanomaterials to be closely monitored by regulatory agencies worldwide motivating research to better understand the relationship between Ag characteristics and antibacterial activity. Nanosilver immobilized on nanostructured silica facilitates such investigations as the SiO2 support hinders the growth of Nanosilver during its synthesis and, most importantly, its flocculation in bacterial suspensions. Here, such composite Ag/silica nanoparticles were made by flame spray pyrolysis of appropriate solutions of Ag-acetate or Ag-nitrate and hexamethyldisiloxane or tetraethylorthosilicate in ethanol, propanol, diethylene glucolmonobutyl ether, acetonitrile or ethylhexanoic acid. The effect of solution composition on Nanosilver characteristics and antibacterial activity against the Gram negative Escherichia coli was investigated by monitoring their recombinantly synthesized green fluorescent protein. Suspensions with identical Ag mass concentration exhibited drastically different antibacterial activity pointing out that the Nanosilver surface area concentration rather than its mass or molar or number concentration determine best its antibacterial activity. Nanosilver made from Ag-acetate showed a unimodal size distribution, while that made from inexpensive Ag-nitrate exhibited a bimodal one. Regardless of precursor composition or Nanosilver size distribution, the antibacterial activity of Nanosilver was correlated best with its surface area concentration in solution.
Robert L Sprando - One of the best experts on this subject based on the ideXlab platform.
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comparative cytotoxicity of Nanosilver in human liver hepg2 and colon caco2 cells in culture
Journal of Applied Toxicology, 2014Co-Authors: Saura C Sahu, Jiwen Zheng, Lesley Graham, Lynn Chen, John Ihrie, Jeffrey J Yourick, Robert L SprandoAbstract:The use of silver nanoparticles in food, food contact materials, dietary supplements and cosmetics has increased significantly owing to their antibacterial and antifungal properties. As a consequence, the need for validated rapid screening methods to assess their toxicity is necessary to ensure consumer safety. This study evaluated two widely used in vitro cell culture models, human liver HepG2 cells and human colon Caco2 cells, as tools for assessing the potential cytotoxicity of food- and cosmetic-related nanoparticles. The two cell culture models were utilized to compare the potential cytotoxicity of 20-nm silver. The average size of the silver nanoparticle determined by our transmission electron microscopy (TEM) analysis was 20.4 nm. The dynamic light scattering (DLS) analysis showed no large agglomeration of the silver nanoparticles. The concentration of the 20-nm silver solution determined by our inductively coupled plasma-mass spectrometry (ICP-MS) analysis was 0.962 mg ml(-1) . Our ICP-MS and TEM analysis demonstrated the uptake of 20-nm silver by both HepG2 and Caco2 cells. Cytotoxicity, determined by the Alamar Blue reduction assay, was evaluated in the Nanosilver concentration range of 0.1 to 20 µg ml(-1) . Significant concentration-dependent cytotoxicity of the Nanosilver in HepG2 cells was observed in the concentration range of 1 to 20 µg ml(-1) and at a higher concentration range of 10 to 20 µg ml(-1) in Caco2 cells compared with the vehicle control. A concentration-dependent decrease in dsDNA content was observed in both cell types exposed to Nanosilver but not controls, suggesting an increase in DNA damage. The DNA damage was observed in the concentration range of 1 to 20 µg ml(-1) . Nanosilver-exposed HepG2 and Caco2 cells showed no cellular oxidative stress, determined by the dichlorofluorescein assay, compared with the vehicle control in the concentration range used in this study. A concentration-dependent decrease in mitochondria membrane potential in both Nanosilver exposed cell types suggested increased mitochondria injury compared with the vehicle control. The mitochondrial injury in HepG2 cells was significant in the concentration range of 1 to 20 µg ml(-1) , but in Caco2 cells it was significant at a higher concentration range of 10 to 20 µg ml(-1) . These results indicated that HepG2 cells were more sensitive to Nanosilver exposure than Caco2 cells. It is generally believed that cellular oxidative stress induces cytotoxicity of nanoparticles. However, in this study we did not detect any Nanosilver-induced oxidative stress in either cell type at the concentration range used in this study. Our results suggest that cellular oxidative stress did not play a major role in the observed cytotoxicity of Nanosilver in HepG2 and Caco2 cells and that a different mechanism of Nanosilver-induced mitochondrial injury leads to the cytotoxicity. The HepG2 and Caco2 cells used this study appear to be targets for silver nanoparticles. The results of this study suggest that the differences in the mechanisms of toxicity induced by Nanosilver may be largely as a consequence of the type of cells used. This differential rather than universal response of different cell types exposed to nanoparticles may play an important role in the mechanism of their toxicity. In summary, the results of this study indicate that the widely used in vitro models, HepG2 and Caco2 cells in culture, are excellent systems for screening cytotoxicity of silver nanoparticles. These long established cell culture models and simple assays used in this study can provide useful toxicity and mechanistic information that can help to better inform safety assessments of food- and cosmetic-related silver nanoparticles.
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comparative genotoxicity of Nanosilver in human liver hepg2 and colon caco2 cells evaluated by fluorescent microscopy of cytochalasin b blocked micronucleus formation
Journal of Applied Toxicology, 2014Co-Authors: Saura C Sahu, Jiwen Zheng, Jeffrey J Yourick, Shambhu Roy, Robert L SprandoAbstract:As a consequence of the increased use of silver nanoparticles in food, food contact materials, dietary supplements and cosmetics to prevent fungal and bacterial growth, there is a need for validated rapid screening methods to assess the safety of nanoparticle exposure. This study evaluated two widely used in vitro cell culture models, human liver HepG2 cells and human colon Caco2 cells, as tools for assessing the potential genotoxicity of 20-nm Nanosilver. The average silver nanoparticle size as determined by transmission electron microscopy (TEM) was 20.4 nm. Dynamic light scattering (DLS) analysis showed no large agglomeration of the silver nanoparticles. The silver concentration in a 20-nm Nanosilver solution determined by the inductively coupled plasma-mass spectrometry (ICP-MS) analysis was 0.962 mg ml(-1) . Analysis by ICP-MS and TEM demonstrated the uptake of 20-nm silver by both HepG2 and Caco2 cells. Genotoxicity was determined by the cytochalasin B-blocked micronucleus assay with acridine orange staining and fluorescence microscopy. Concentration- and time-dependent increases in the frequency of binucleated cells with micronuclei induced by the Nanosilver was observed in the concentration range of 0.5 to 15 µg ml(-1) in both HepG2 and Caco2 cells compared with the control. Our results indicated that HepG2 cells were more sensitive than Caco2 cells in terms of micronuclei formation induced by Nanosilver exposure. In summary, the results of this study indicate that the widely used in vitro models, HepG2 and Caco2 cells in culture, represent potential screening models for prediction of genotoxicity of silver nanoparticles by in vitro micronucleus assay.
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comparative genotoxicity of Nanosilver in human liver hepg2 and colon caco2 cells evaluated by fluorescent microscopy of cytochalasin b blocked micronucleus formation
Journal of Applied Toxicology, 2014Co-Authors: Saura C Sahu, Jiwen Zheng, Jeffrey J Yourick, Robert L SprandoAbstract:As a consequence of the increased use of silver nanoparticles in food, food contact materials, dietary supplements and cosmetics to prevent fungal and bacterial growth, there is a need for validated rapid screening methods to assess the safety of nanoparticle exposure. This study evaluated two widely used in vitro cell culture models, human liver HepG2 cells and human colon Caco2 cells, as tools for assessing the potential genotoxicity of 20-nm Nanosilver. The average silver nanoparticle size as determined by transmission electron microscopy (TEM) was 20.4 nm. Dynamic light scattering (DLS) analysis showed no large agglomeration of the silver nanoparticles. The silver concentration in a 20-nm Nanosilver solution determined by the inductively coupled plasma–mass spectrometry (ICP-MS) analysis was 0.962 mg ml−1. Analysis by ICP-MS and TEM demonstrated the uptake of 20-nm silver by both HepG2 and Caco2 cells. Genotoxicity was determined by the cytochalasin B-blocked micronucleus assay with acridine orange staining and fluorescence microscopy. Concentration- and time-dependent increases in the frequency of binucleated cells with micronuclei induced by the Nanosilver was observed in the concentration range of 0.5 to 15 µg ml−1 in both HepG2 and Caco2 cells compared with the control. Our results indicated that HepG2 cells were more sensitive than Caco2 cells in terms of micronuclei formation induced by Nanosilver exposure. In summary, the results of this study indicate that the widely used in vitro models, HepG2 and Caco2 cells in culture, represent potential screening models for prediction of genotoxicity of silver nanoparticles by in vitro micronucleus assay. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
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comparative genotoxicity of Nanosilver in human liver hepg2 and colon caco2 cells evaluated by a flow cytometric in vitro micronucleus assay
Journal of Applied Toxicology, 2014Co-Authors: Saura C Sahu, Jeffrey J Yourick, Joyce Njoroge, Steven M Bryce, Robert L SprandoAbstract:Two widely used in vitro cell culture models, human liver HepG2 cells and human colon Caco2 cells, and flow cytometry techniques were evaluated as tools for rapid screening of potential genotoxicity of food-related Nanosilver. Comparative genotoxic potential of 20 nm silver was evaluated in HepG2 and Caco2 cell cultures by a flow cytometric-based in vitro micronucleus assay. The Nanosilver, characterized by the dynamic light scattering, transmission electron microscopy and inductively coupled plasma–mass spectrometry analysis, showed no agglomeration of the silver nanoparticles. The inductively coupled plasma–mass spectrometry and transmission electron microscopy analysis demonstrated the uptake of 20 nm silver by both cell types. The 20 nm silver exposure of HepG2 cells increased the concentration-dependent micronucleus formation sevenfold at 10 µg ml–1 concentration in attached cell conditions and 1.3-fold in cell suspension conditions compared to the vehicle controls. However, compared to the vehicle controls, the 20 nm silver exposure of Caco2 cells increased the micronucleus formation 1.2-fold at a concentration of 10 µg ml–1 both in the attached cell conditions as well as in the cell suspension conditions. Our results of flow cytometric in vitro micronucleus assay appear to suggest that the HepG2 cells are more susceptible to the Nanosilver-induced micronucleus formation than the Caco2 cells compared to the vehicle controls. However, our results also suggest that the widely used in vitro models, HepG2 and Caco2 cells and the flow cytometric in vitro micronucleus assay are valuable tools for the rapid screening of genotoxic potential of Nanosilver and deserve more careful evaluation. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Georgios A Sotiriou - One of the best experts on this subject based on the ideXlab platform.
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enhanced ag ion release from aqueous Nanosilver suspensions by absorption of ambient co2
Langmuir, 2015Co-Authors: Kakeru Fujiwara, Georgios A Sotiriou, Sotiris E PratsinisAbstract:Nanosilver with closely controlled average particle diameter (7–30 nm) immobilized on nanosilica is prepared and characterized by X-ray diffraction, N2 adsorption, and transmission electron microscopy. The presence of Ag2O on the as-prepared Nanosilver surface is confirmed by UV–vis spectroscopy and quantified by thermogravimetric analysis and mass spectrometry. The release of Ag+ ions in deionized water is monitored electrochemically and traced quantitatively to the dissolution of a preexisting Ag2O monolayer on the Nanosilver surface. During this dissolution, the pH of the host solution rapidly increases, suppressing dissolution of the remaining metallic Ag. When, however, a Nanosilver suspension is exposed to a CO2-containing atmosphere, like ambient air during its storage or usage, then CO2 is absorbed by the host solution decreasing its pH and contributing to metallic Ag dissolution and further leaching of Ag+ ions. So the release of Ag+ ions from the above closely sized Nanosilver solutions in the a...
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toxicity of silver nanoparticles in macrophages
Small, 2013Co-Authors: Anna Pratsinis, Pablo Hervella, Jeanchristophe Leroux, Sotiris E Pratsinis, Georgios A SotiriouAbstract:Silver nanoparticles (Nanosilver) are broadly used today in textiles, food packaging, household devices and bioapplications, prompting a better understanding of their toxicity and biological interactions. In particular, the cytotoxicity of Nanosilver with respect to mammalian cells remains unclear, because such investigations can be biased by the Nanosilver coatings and the lack of particle size control. Here, Nanosilver of well-defined size (5.7 to 20.4 nm) supported on inert nanostructured silica is produced using flame aerosol technology. The cytotoxicity of the prepared Nanosilver with respect to murine macrophages is assessed in vitro because these cells are among the first to confront Nanosilver upon its intake by mammals. The silica support facilitates the dispersion and stabilization of the prepared Nanosilver in biological suspensions, and no other coating or functionalization is applied that could interfere with the biointeractions of Nanosilver. Detailed characterization of the particles by X-ray diffraction and electron microscopy reveals that the size of the Nanosilver is well controlled. Smaller Nanosilver particles release or leach larger fractions of their mass as Ag⁺ ions upon dispersion in water. This strongly influences the cytotoxicity of the Nanosilver when incubated with murine macrophages. The size of the Nanosilver dictates its mode of cytotoxicity (Ag⁺ ion-specific and/or particle-specific). The toxicity of small Nanosilver ( 10 nm). Direct silver nanoparticle-macrophage interactions dominate the Nanosilver toxicity at sizes larger than 10 nm.
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quantifying the origin of released ag ions from Nanosilver
Langmuir, 2012Co-Authors: Georgios A Sotiriou, Andreas Meyer, Sven Panke, Jesper T N Knijnenburg, Sotiris E PratsinisAbstract:Nanosilver is most attractive for its bactericidal properties in modern textiles, food packaging, and biomedical applications. Concerns, however, about released Ag+ ions during dispersion of Nanosilver in liquids have limited its broad use. Here, Nanosilver supported on nanostructured silica is made with closely controlled Ag size both by dry (flame aerosol) and by wet chemistry (impregnation) processes without any surface functionalization that could interfere with its ion release. It is characterized by electron microscopy, atomic absorption spectroscopy, and X-ray diffraction, and its Ag+ ion release in deionized water is monitored electrochemically. The dispersion method of Nanosilver in solutions affects its dissolution rate but not the final Ag+ ion concentration. By systematically comparing Nanosilver size distributions to their equilibrium Ag+ ion concentrations, it is revealed that the latter correspond precisely to dissolution of one to two surface silver oxide monolayers, depending on particle ...
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engineering Nanosilver as an antibacterial biosensor and bioimaging material
Current opinion in chemical engineering, 2011Co-Authors: Georgios A Sotiriou, Sotiris E PratsinisAbstract:The capacity of Nanosilver (Ag nanoparticles) to destroy infectious micro-organisms makes it one of the most powerful antimicrobial agents, an attractive feature against ‘super-bugs’ resistant to antibiotics. Furthermore, its plasmonic properties facilitate its employment as a biosensor or bioimaging agent. Here, the interaction of Nanosilver with biological systems including bacteria and mammalian cells is reviewed. The toxicity of Nanosilver is discussed focusing on Ag+ ion release in liquid solutions. Biomedical applications of Nanosilver are also presented capitalizing on its antimicrobial and plasmonic properties and summarizing its advantages, limitations and challenges. Though a lot needs to be learned about the toxicity of Nanosilver, enough is known to safely use it in a spectrum of applications with minimal impact to the environment and human health.
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Nanosilver on nanostructured silica antibacterial activity and ag surface area
Chemical Engineering Journal, 2011Co-Authors: Georgios A Sotiriou, Alexandra Teleki, Adrian Camenzind, Frank Krumeich, Andreas Meyer, Sven Panke, Sotiris E PratsinisAbstract:Nanosilver is one of the first nanomaterials to be closely monitored by regulatory agencies worldwide motivating research to better understand the relationship between Ag characteristics and antibacterial activity. Nanosilver immobilized on nanostructured silica facilitates such investigations as the SiO2 support hinders the growth of Nanosilver during its synthesis and, most importantly, its flocculation in bacterial suspensions. Here, such composite Ag/silica nanoparticles were made by flame spray pyrolysis of appropriate solutions of Ag-acetate or Ag-nitrate and hexamethyldisiloxane or tetraethylorthosilicate in ethanol, propanol, diethylene glucolmonobutyl ether, acetonitrile or ethylhexanoic acid. The effect of solution composition on Nanosilver characteristics and antibacterial activity against the Gram negative Escherichia coli was investigated by monitoring their recombinantly synthesized green fluorescent protein. Suspensions with identical Ag mass concentration exhibited drastically different antibacterial activity pointing out that the Nanosilver surface area concentration rather than its mass or molar or number concentration determine best its antibacterial activity. Nanosilver made from Ag-acetate showed a unimodal size distribution, while that made from inexpensive Ag-nitrate exhibited a bimodal one. Regardless of precursor composition or Nanosilver size distribution, the antibacterial activity of Nanosilver was correlated best with its surface area concentration in solution.
Rangasamy Jayakumar - One of the best experts on this subject based on the ideXlab platform.
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preparation and characterization of novel β chitin Nanosilver composite scaffolds for wound dressing applications
Carbohydrate Polymers, 2010Co-Authors: P Sudheesh T Kumar, Suryan Abhilash, K Manzoor, Shantikumar V Nair, Hiroshi Tamura, Rangasamy JayakumarAbstract:Abstract We developed novel β-chitin/Nanosilver composite scaffolds for wound healing applications using β-chitin hydrogel with silver nanoparticles. The prepared Nanosilver particles and nanocomposite scaffolds were characterized using SEM, FT-IR, XRD and TGA studies. The antibacterial, blood-clotting, swelling, cell attachment and cytotoxicity studies of the prepared composite scaffolds were evaluated. The prepared β-chitin/Nanosilver composite scaffolds were bactericidal against Escherichia coli and Staphylococcus aureus and it showed good blood-clotting ability as well. Cell attachment studies using vero (epithelial) cells showed that the cells were well attached on the scaffolds. These results suggested that β-chitin/Nanosilver composite scaffold could be a promising candidate for wound dressing applications.
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development of novel chitin Nanosilver composite scaffolds for wound dressing applications
Journal of Materials Science: Materials in Medicine, 2010Co-Authors: K Madhumathi, P Sudheesh T Kumar, Suryan Abhilash, V Sreeja, K Manzoor, Shantikumar V Nair, Hiroshi Tamura, Rangasamy JayakumarAbstract:Antibiotic resistance of microorganisms is one of the major problems faced in the field of wound care and management resulting in complications like infection and delayed wound healing. Currently a lot of research is focused on developing newer antimicrobials to treat wounds infected with antibiotic resistant microorganisms. Silver has been used as an antimicrobial agent for a long time in the form of metallic silver and silver sulfadiazine ointments. Recently silver nanoparticles have come up as a potent antimicrobial agent and are finding diverse medical applications ranging from silver based dressings to silver coated medical devices. Chitin is a natural biopolymer with properties like biocompatibility and biodegradability. It is widely used as a scaffold for tissue engineering applications. In this work, we developed and characterized novel chitin/Nanosilver composite scaffolds for wound healing applications. The antibacterial, blood clotting and cytotoxicity of the prepared composite scaffolds were also studied. These chitin/Nanosilver composite scaffolds were found to be bactericidal against S. aureus and E. coli and good blood clotting ability. These results suggested that these chitin/Nanosilver composite scaffolds could be used for wound healing applications.
Aparna Watal - One of the best experts on this subject based on the ideXlab platform.
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Nanosilver and global public health international regulatory issues
Social Science Research Network, 2010Co-Authors: Thomas Faunce, Aparna WatalAbstract:Silver in nanoparticle form is used extensively worldwide in hospital and general practice settings in dressings as a treatment for external wounds, burns, and ulcers. Nanosilver also is an increasingly important coating over embedded medical devices, inhibiting the development of biofilm. Nanosilver disinfectant sprays and polymer coatings are being widely promoted as protective against viral infections. Nanosilver additionally is widely used for its anti-bacterial properties in food processing and packaging, as well as consumer products used for domestic cleaning and clothing. This article argues that medical devices, therapeutic products and domestic food and goods containing Nanosilver, though offering therapeutic benefits, must be subject to precautionary regulation because of associated public health and environmental risks, particularly from large volumes of Nanosilver in waste water. It first examines the use of Nanosilver in a variety of contemporary medical and domestic products and this utilization may assist in resolving global public health problems such as restricted access to safe food, water and medical care. It then discusses the mechanisms of toxicity for Nanosilver, whether it should be classified as a new chemical entity for regulatory purposes and whether its increased usage poses significant environmental and public health risks. The article next critically analyses representative international regulatory regimes (the United States, European Union, United Kingdom and Australia) for medical and domestic use of Nanosilver. The conclusion includes a set of recommendations for improving international regulation of Nanosilver in terms of both its safety and potential positive contribution to global public health. Author's proof copy.
